Paying tribute to the great watchmakers who wrote the history, de Grisogono reinterprets one of the supreme horological complications – the tourbillon – in a timepiece combining age-old arts and ultra-modern techniques and offering a flying tourbillon fitted with a balance-staff inclined at a 30° angle.
At the time, this kind of movement had been designed for a pocket watch. According to the literature, Richard Daners had drawn inspiration from the work of his peers, and notably the flying tourbillon created by Alfred Helwig; as well as the first tourbillon with inclined balance-wheel developed for travel clocks and built by Albert Potter in 1860.
Given that the position of a wristwatch frequently shifts between vertical and horizontal planes, the effect of the tourbillon is less pronounced, since the plat-pendu phenomenon lead to a loss in timekeeping performance in watches equipped with this device. To alleviate the problem of gravity’s influence on a wristwatch escapement independently of its direction, de Grisogono has gone beyond the traditional tourbillon to create a flying tourbillon fitted with a balance-staff inclined at a 30° angle.
The choice of the 30° slant was determined by both technical and aesthetic reasons. On the one hand, this angle improves precision by placing the balance-staff in the best possible position; and on the other, on an aesthetic level, a larger angle would have implied significantly increasing the height (thickness) of the model in order to leave enough space for the flying tourbillon.
In terms of rating, given that the tourbillon carriage and the balance-staff are no longer on the same plane, this movement required the development of specific measurement techniques designed to achieve the best possible average between the rates.
In a classic tourbillon, the carriage is held on one side by a bridge and on the other by a pivot, or indeed sometimes by two bridges on either side. de Grisogono tourbillon features a ceramic ball bearing mechanism that notably ensures greater shock resistance.
In order to achieve a high degree of isochronism, the parts composing the tourbillon are made from low-density materials that make them extremely light. The flying tourbillon performing one rotation per minute (the most usual cadence) has been offset to 6 o’clock, an original choice that highlights the ingenious construction of the watch and asserts the distinctive character of de Grisogono creations. Moreover, its escapement has also been modified and is now also inclined, revealing an original cone-shaped gear for the fourth wheel (driving the seconds) and the pinions.
This wealth of well-mastered details is on display beneath an elegant and daring three-dimensional sapphire lens.
The Instrumento N°Uno Tourbillon houses the automatic rectangular-shaped Calibre TB 31-00 in which the 266 components are fully revealed through the see-through case. It is equipped with a twin barrel and has a 72-hour power reserve. Its mainplate and bridges are skeleton-worked, graced with polished angles and clothed with a matt black PVD coating. In a nod to the brand’s jewellery background, the spoke of the skeleton-worked oscillating weight is adorned with a diamond-shaped opening. The tourbillon itself is composed of 62 parts weighing just 3.6 grams.
de Grisogono has developed a totally innovative case with redesigned proportions reaching a generous volume of 59.2 mm x 33 mm x 14.99 mm, composed of a hybrid sapphire and precious metal structure. The unique construction of its case is composed of rose or white gold, while the bezel as well as the case-back are all made of sapphire.
Further reinforcing its unique character, the Instrumento N°Uno Tourbillon has no dial. The hours are marked off on a horseshoe-shaped flying disc directly placed on the mainplate and bearing the emblematic de Grisogono stylised Arabic numerals. The crown set with a black diamond also features an original structure in that its heart is made of rose or white gold clothed in sapphire.